Generally speaking an EAS system is a technology used to identify articles as they pass through a gated area. This identification is used to alert someone that unauthorized removal of items is being attempted.
In EAS systems, there can be the situation that the scanner DoF is longer than the EAS effective distance. In this case, the barcode can be read at the far end of the DoF, which may be a distance that is greater than the EAS effective distance. This situation means that the EAS tag that is co-located with the barcode on the product would not be deactivated since the EAS tag is out of EAS effective range. Since the EAS tag is not deactivated, an alarm would be activated when the customer passes through the security system of the store even though the customer purchased the article.
Therefore, there exists a need to manage the effective range of an EAS system relative to the depth of field (DoF) of the scanner to avoid such customer dissatisfaction situations.